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Footprint / Land Pattern Naming Convention

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Artwork Master ITALY View Drop Down
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    Posted: 18 Mar 2012 at 10:12am
Hi, in the document "PCB Design Optimization Starts in the CAD Library.pdf" at page 21 it is defined a 3 letters of code for distinguish each electronic Manufacturer of components.
Is it possible see the actually list of them before the program of building the decals will be ready? (probably before the date of May 1 2012) so we can contribute to enhance this list!
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Tom H View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Tom H Quote  Post ReplyReply Direct Link To This Post Posted: 18 Mar 2012 at 10:48am
Please send me a private message "off-line" or if you know my email address and I will send you the list of Component Manufacturer's and the 2 - 3 character code.
 
The creation of the 2 - 3 character suffix is still in the works, so if you want to help define the abbreviations that will be great too.
 
The new PCB Footprint Calculator will have the list of component manufacturer's built in to automate the Footprint (Land Pattern) Name.
 
 


Edited by Tom H - 18 Mar 2012 at 10:49am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Tom H Quote  Post ReplyReply Direct Link To This Post Posted: 18 Mar 2012 at 11:14am
We are currently working on the "Mil Unit" Footprint (Land Pattern) Naming Convention document.
 
Both the Mil and Metric Land Pattern name documents will be posted soon.
 
There are many updated documents that will be posted soon.
 - Component Manufacturer list with the completed abbreviations
 - Mil & Metric Land Pattern Names
 - Mil & Metric Padstack Naming Convention
 - Mounting Holes & PCB Hardware
 - Footprint Zero Component Orientations
 - Reference Designators
 
But the largest collection of Footprint (Land Pattern) creation data will be in the "PCB Library Construction Guidelines" section -
 
The primary reason for adding "mil units" is that PCB Fabrication, CAD Vendors and most companies that do PCB layout have not transitioned to the Metric measurement system. There is not 1 PCB Fabrication shop in the USA that prefers Metric Unit Gerber data, Drill Data, Drawings, Laminate Stack-ups, Copper Weight or any aspect of fabrication PCB construction. Some tolerate Metric Units, but behind the scenes they convert Metric Units to Mil (Inch) Units. As PCB Designers, we were always taught DFM (Design For Manufacturing) and if the PCB manufacturer's don't want Metric Unit data then PCB Designers are not designing for DFM.
 
The new "PCB Footprint Expert" will default to Mil Units for library construction, just like every CAD vendors tool set. The User can switch to Metric Units to insert component dimensions and then switch to Mil Units for Footprint creation. Every value of the Footprint features will be rounded off in 1 Mil increments and Footprint & Padstack names will be Mil Units.
 


Edited by Tom H - 23 Mar 2012 at 11:36am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Matija Quote  Post ReplyReply Direct Link To This Post Posted: 23 Mar 2012 at 10:26am
Hello Tom,

this is the biggest disappointment that I ever heard: Predominant measurement system to be Mil units for a library service that is supposed to be used world wide and be truly global.

There are two main reasons I am disappointed. The one is "political" the other is "technical"

The political one:
Please take in account that the there is more to the world as only continental US.
When I read "... and most companies that do PCB layout have not transitioned to the Metric measurement system. There is not 1 PCB Fabrication shop in the USA that prefers Metric Unit...", I am also wondering did you ever realize that there are people who never heard of Mil Units. Our PCB producre here in Europe does everything in Metric. We set up rules in metric, design in metric, produce and assemble in metric, etc... I could just say the same phrase the other way around "...... and most companies that do PCB layout have not transitioned to the Mil Units measurement system. !!!"

As much as I respect your work and your idea, this unit choice is catastrophic, and shows a lot of "close mindedness" on the world as a global.

And now the technical point:
You can always convert a metric unit back to a Mil unit without loss of precision. The other way around it is not the case, due to rounding errors.

Please reconsider your choice and since PcbLibraies is menat to be a reference point for everyone designing libraires,  force the use of both with preference to the metric unit as native unit.

Regards
  Matija

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Tom H View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Tom H Quote  Post ReplyReply Direct Link To This Post Posted: 23 Mar 2012 at 11:31am

There is a misunderstanding about the Default Units. We are creating a "Dashboard" that appears when the user opens the PCB Footprint Calculator that allows you to pick what Measurement Units you want the program to default to.

 

We have implemented provision options in the new PCB Footprint Calculator to allow the User to -

 

o   Always default Land Pattern and Padstack Names to Metric units

o   Use Metric Land Pattern and Padstack Names when using metric units

o   Use Mil Land Pattern and Padstack Names when using mil units

 

The globally the CAD Vendors default units are mils. There are PCB designers worldwide that are doing PCB layout in mil units. There are PCB manufacturers worldwide (especially in China and India) that prefer mil units for PCB fabrication.

 

Your argument is not with PCB Libraries, Inc. You need to take it to the PCB fabrication shops and convince them to transition to the metric unit system. Everywhere I look in the USA, PCB designers are being held back from transitioning to metric because their PCB fabrication shops prefer mil unit data.

 

The free PCB Footprint Calculator that will become available on May 1, 2012 will have the ability to save component dimensions and manufacturer attributes (including datasheet web-links) in an .fpx file. You can upload your .fpx files to our server and we’ll sell them for you, giving you a 25% lifetime royalty. The library customers will have a “PCB Footprint Expert” that will import .fpx files and auto-save the component manufacturer's data to the customers master .fpx library on their server and auto-generate the PCB library part using their personal preferences for Silkscreen & Assembly line widths, Ref Des sizes, Footprint Rotation (IPC, IEC, EIA), Origin, Measurement Units, Land Pattern and Padstack Name (there are too many personal preferences to list them all) and export the PCB library part to their native CAD tool format. There will be hundreds of thousands of library parts available on a web-based Vending Machine in a neutral format and the End User can output whatever "preferences" they choose.

 

What's catastrophic is the lack of commitment from the PCB fabrication industry to transition to the metric unit system and they're holding back "Electronic Product Development Automation". If all PCB designers would ban together and only provide their manufacturer's metric data then the fabrication shop might transition. Let's all work together to migrate the entire electronics industry to metric units. However, there are PCB designers who are near retirement who have no intention of ever learning the metric unit system. There are service bureaus who must use Imperial measurements because their customers demand it.

 

We are creating a new tool and service that will provide the largest amount of library content in the world. We hope to cover all bases to make everyone productive.

 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dale Quote  Post ReplyReply Direct Link To This Post Posted: 21 May 2012 at 7:05pm
Re units, personally I think the decision to formally allow mils will delay the ultimate transition to metric by many years, extending the dual-units pain and cost to yet another generation of designers.

Re land pattern design and naming: The footprint calculator seems to assume that there will always be just one data sheet from which the component dimensions are transcribed - and the naming allows us to identify THE manufacturer. i.e. single sourcing.
Maybe single-sourcing is common in some industries/fields, but in the 30+ years I have been involved in the electronics design and manufacturing industry it has been the exception. Engineers have always had to get special permission to design in a single-sourced part.
Is the footprint calculator making any concessions to the needs of us who must consider multiple very similar packages when designing footprints?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Tom H Quote  Post ReplyReply Direct Link To This Post Posted: 21 May 2012 at 9:09pm
Hey Mate,
 
PCB Libraries, Inc. is not in the business of telling customers what measurements units are best for them. And we do not support single vendor for component selection. Rather we support multiple vendor sources for every electronic device used in PCB layout. That's why we are creating the world's largest PCB Library Vending Machine based on component manufacturer's part numbers for easy search, find, cross-reference and download. However, or database will offer both mil and millimeter based library parts and our best guess is that the mil based library parts will out sell the metric library parts for the next 10 years.
 
I applaud your effort for the electronics industry to transition to the metric measurement system, but you need to take your case up with every PCB fabrication shop in the USA. They ALL prefer mil unit fabrication drawings and Gerber data and until they transition the PCB designers in America will never transition.
 
I would also take a case up with the component manufacturers who call there chip components named after mil units - 0201, 0402, 0603, 0805, 1206, etc. The component manufacturers need to stop the proliferation on the mil unit system, especially in their marketing of imperial unit component names.
 
What about all the PCB fab material providers like Isola, Rogers and others who predominately create mil based fabrication materials for the PCB fabrication vendors. American fabrication has now successfully introduced and transitioned Chinese fabrication shops to mil units. Yes, we taught the Chinese workers how to work in mil units.
 
How about Polar Instruments with their impedance calculator defaulting to mil units for PCB fabrication impedance control.
 
Or what about all the CAD vendors who create CAD tool installations using mil units as their default units.
 
OK, I mentioned PCB fabricators, material providers, component manufacturer's, impedance control calculations and CAD vendors. You should take up your position with them and when they convert we'll gladly convert with them.
 
PCB Libraries, Inc. has been on the metric bandwagon for the past 10 years and nothing has changed. Our tools support the metric measurement system 100% and we are greatly advanced in the metric unit system. It just so happens that our tools are very mil unit friendly too. I'm not sure that our efforts will postone the transition of anyone to the metric measurement system. It's the other vendors that are responsible for the delay of standardization to a single measurement system. Transitioning to a universal measurement system would greatly simplify our job, our tools and the global electronics industry, but it's not reality (yet).  Confused
 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dale Quote  Post ReplyReply Direct Link To This Post Posted: 21 May 2012 at 11:42pm
Oops, looks like I hit a raw nerve - nothing personal was intended.
In principle I agree with everything you say, however I have much less influence than you.
I have long noted that PCB Libraries has been on the metric bandwagon and have privately applauded those efforts. What I was perceiving was the Imperial stalwarts grinding you down.

Slightly off the subject - I wish more US software vendors would look at the Windows Regional settings and use that as the default. Sadly Adobe and Mentor (to name two major vendors whose software I use) think everyone prefers Imperial by default; you want something else?, then you chase down the settings if they exist. Not very user friendly in that regard.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Tom H Quote  Post ReplyReply Direct Link To This Post Posted: 22 May 2012 at 9:20am
I joined IPC to help them transition the PCB industry from Imperial Units to the Metric Unit system. Every Power Point presentation I gave in the past 10 years only contained metric units. The 1st Land Pattern Calculator we created only supported metric units for the first 5 years of it's existence.
 
I pounded the industry with a call to transition publically speaking at 5 - 7 conferences every year for 10 years. As the president of PCB Libraries, Inc. I surrounded myself with everything metric and I burned all knowledge of the Imperial unit system.
 
Then Valor took over the tools and sent me all over the world to train and teach others. But then Mentor Graphics came along and took over Valor. I worked at Mentor and tried to convince the developers that all CAD tool installations should default to metric units and that all PCB training classes should be taught using metric units. My recommendations fell on deaf ears and then I was fired.
 
Then I re-entered the PCB design workforce and tried to find a company to work for that adopted the metric unit system and that task was impossible. I submitted 50 different job applications into companies looking to hire PCB designers but all of them were using the Imperial unit system. So I eventually took a job with CADParts Consulting service bureau for several DOD companies and every library part I create and everything I design is in Imperial units because that is what their customer's want. I can't fight anymore to be the poster boy for the metric measurement system. I know in my heart that metric units are far superior to Imperial units for PCB design layout, but I cannot die on that hill simply because PCB fabrication won't transition.
 
For 10 years under PCB Libraries, Inc. I was in a metric world, but no other PCB vendors were. I tried to help IPC transition the industry from Imperial to Metric units, but IPC failed to communicate the transition to PCB fabrication shops. As a PCB designer, everything we do must be for DFM (Design For Manufacturing) and all the manufacturer's preach mil units to all their customers. The transition will only take root when PCB fabrication prefers metric units. And IPC, JEDEC, EIA, NIST, ANSI, IEC and all the world standards stand helplessly by the metric unit system while PCB fabrication ignores their call for unity and standardization under the umbrella of a single global unit system.
 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Nick B Quote  Post ReplyReply Direct Link To This Post Posted: 22 May 2012 at 10:05am
Dale, we're building an infrastructure to help anyone facilitate an "easy" transition to metric. Our vision remains 100% intact, only we're using a very different strategy now. We have to rebuild everything from scratch (software, apps, site, etc), so it goes without saying we have to deal with a bit of a setback. However, long term we want to support both systems and let the industry decide when it is ready for transition. Whenever that is, we'll be there for 100% support.
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